it is tech tho
quick standup? thats big
its a tool that was known by some and not by others but none the less still a viable "tech"
A "tech" would be something that is not only accessible to characters but is also practical and can be used openly.
The splat tech? Quick stand-up? Its all good until you realize that this is just normal move function.
If it were just f.3? Yeah, that's nifty and would be a tech. If it were just splats? Even that would be a tech...
But this is just how some moves work. You can do a quick stand off of a splat, a soft knockdown, hell most characters can force a quick stand off of linking together two d.2s. I don't use a 123 string and call it tech, because frankly its something that comes with the character. Its nothing special or new, its not something that requires any special mechanic to take advantage of, and at that its an impractical example. I can do a fast stand with more or less 8 of Bane's normal attacks and about 4 of his strings, it stops becoming a "tech" and turns into attack function. You guys are late to the party, yeah, you never bothered to look into this stuff, but its not tech.
And viability is questionable since for the most part you are trading in bigger damage and BnB combos to try and time these stands, unless you are someone like Bane who thrives on resets and the like and has multiple known options to work with it isn't going to be worth it overall. There's enders that leave you at more advantage, do more damage, carry further, are just overall better.
tl;dr: If this was a tech, it would change how people play the game. Flatly, anyone whom will be using this has probably already found it, anyone who hasn't... Welcome to the level of week 1 Bane. Its how the moves work, it works for a multitude of them and its just how they function.